Here's more information on the biology of the white musselcracker (from Mann, 2000)
Maximum age: 31 years
Spawning season: August-January
Age at 50% maturity: 5.4 years
Length at 50% maturity: 35 cm (Fork Length)
Mann, B. (2000). Southern African marine linefish status reports. Special Publication 7. ORI, Durban.